Changes to the DBBE. Moving toward having many more
backend driver choices. (CVS 176)
FossilOrigin-Name: c0730217a04323a1a73d125e3e7da32bcc8d58fc
diff --git a/src/dbbe.c b/src/dbbe.c
index 43948c1..907aa73 100644
--- a/src/dbbe.c
+++ b/src/dbbe.c
@@ -30,7 +30,7 @@
** relatively simple to convert to a different database such
** as NDBM, SDBM, or BerkeleyDB.
**
-** $Id: dbbe.c,v 1.21 2000/10/19 14:10:09 drh Exp $
+** $Id: dbbe.c,v 1.22 2001/01/13 14:34:06 drh Exp $
*/
#include "sqliteInt.h"
@@ -62,3 +62,90 @@
}
return sqliteGdbmOpen(zName, writeFlag, createFlag, pzErrMsg);
}
+
+/*
+** Open a temporary file. The file should be deleted when closed.
+**
+** Note that we can't use the old Unix trick of opening the file
+** and then immediately unlinking the file. That works great
+** under Unix, but fails when we try to port to Windows.
+*/
+int sqliteDbbeOpenTempFile(Dbbe *pBe, FILE **ppFile){
+ char *zFile; /* Full name of the temporary file */
+ char zBuf[50]; /* Base name of the temporary file */
+ int i; /* Loop counter */
+ int limit; /* Prevent an infinite loop */
+ int rc = SQLITE_OK; /* Value returned by this function */
+ char *zDir; /* Directory to hold the file */
+
+ for(i=0; i<pBe->nTemp; i++){
+ if( pBe->apTemp[i]==0 ) break;
+ }
+ if( i>=pBe->nTemp ){
+ pBe->nTemp++;
+ pBe->apTemp = sqliteRealloc(pBe->apTemp, pBe->nTemp*sizeof(FILE*) );
+ pBe->azTemp = sqliteRealloc(pBe->azTemp, pBe->nTemp*sizeof(char*) );
+ }
+ if( pBe->apTemp==0 ){
+ *ppFile = 0;
+ return SQLITE_NOMEM;
+ }
+ limit = 4;
+ zFile = 0;
+ zDir = pBe->zDir;
+ if( zDir==0 ){
+ zDir = "./";
+ }
+ do{
+ sqliteRandomName(zBuf, "/_temp_file_");
+ sqliteFree(zFile);
+ zFile = 0;
+ sqliteSetString(&zFile, zDir, zBuf, 0);
+ }while( access(zFile,0)==0 && limit-- >= 0 );
+ *ppFile = pBe->apTemp[i] = fopen(zFile, "w+");
+ if( pBe->apTemp[i]==0 ){
+ rc = SQLITE_ERROR;
+ sqliteFree(zFile);
+ pBe->azTemp[i] = 0;
+ }else{
+ pBe->azTemp[i] = zFile;
+ }
+ return rc;
+}
+
+/*
+** Close a temporary file opened using sqliteGdbmOpenTempFile()
+*/
+void sqliteDbbeCloseTempFile(Dbbe *pBe, FILE *f){
+ int i;
+ for(i=0; i<pBe->nTemp; i++){
+ if( pBe->apTemp[i]==f ){
+ unlink(pBe->azTemp[i]);
+ sqliteFree(pBe->azTemp[i]);
+ pBe->apTemp[i] = 0;
+ pBe->azTemp[i] = 0;
+ break;
+ }
+ }
+ fclose(f);
+}
+
+/*
+** Close all temporary files that happen to still be open.
+** This routine is called when the database is being closed.
+*/
+void sqliteDbbeCloseAllTempFiles(Dbbe *pBe){
+ int i;
+ for(i=0; i<pBe->nTemp; i++){
+ if( pBe->apTemp[i]!=0 ){
+ unlink(pBe->azTemp[i]);
+ fclose(pBe->apTemp[i]);
+ sqliteFree(pBe->azTemp[i]);
+ pBe->apTemp[i] = 0;
+ pBe->azTemp[i] = 0;
+ break;
+ }
+ }
+ sqliteFree(pBe->azTemp);
+ sqliteFree(pBe->apTemp);
+}
diff --git a/src/dbbe.h b/src/dbbe.h
index 7c54a77..7d524cb 100644
--- a/src/dbbe.h
+++ b/src/dbbe.h
@@ -28,7 +28,7 @@
** This library was originally designed to support the following
** backends: GDBM, NDBM, SDBM, Berkeley DB.
**
-** $Id: dbbe.h,v 1.8 2000/10/19 01:49:02 drh Exp $
+** $Id: dbbe.h,v 1.9 2001/01/13 14:34:06 drh Exp $
*/
#ifndef _SQLITE_DBBE_H_
#define _SQLITE_DBBE_H_
@@ -53,7 +53,7 @@
*/
typedef struct Dbbe Dbbe;
typedef struct DbbeCursor DbbeCursor;
-
+typedef struct DbbeMethods DbbeMethods;
/*
** Open a complete database.
@@ -65,10 +65,13 @@
Dbbe *sqliteDbbeOpen(const char *zName, int write, int create, char **pzErr);
/*
-** This is the structure returned by sqliteDbbeOpen(). It contains pointers
-** to all access routines for the database backend.
+** Each of the various SQLite backends defines a set of methods for
+** accessing the database. Pointers to the methods are contained in
+** an instance of the following structure. A pointer to a static instance
+** of this structure is assigned to the Dbbe structure that sqlileDbbeOpen
+** returns.
*/
-struct Dbbe {
+struct DbbeMethods {
/* Close the whole database. */
void (*Close)(Dbbe*);
@@ -149,4 +152,22 @@
void (*CloseTempFile)(Dbbe *, FILE *);
};
+/*
+** This is the structure returned by sqliteDbbeOpen(). It contains
+** information common to all the different backend drivers.
+**
+** The information in this structure (with the exception the method
+** pointers in the Dbbe.x field) is intended to be visible to
+** the backend drivers only. Users should not access or modify
+** this structure in any way other than the read the method pointers
+** in Dbbe.x.
+*/
+struct Dbbe {
+ struct DbbeMethods *x; /* Backend-specific methods for database access */
+ char *zDir; /* The directory containing the database file(s) */
+ int nTemp; /* Number of temporary files created */
+ FILE **apTemp; /* Space to hold temporary file pointers */
+ char **azTemp; /* Names of the temporary files */
+};
+
#endif /* defined(_SQLITE_DBBE_H_) */
diff --git a/src/dbbegdbm.c b/src/dbbegdbm.c
index 1e27020..6c2659a 100644
--- a/src/dbbegdbm.c
+++ b/src/dbbegdbm.c
@@ -30,7 +30,7 @@
** relatively simple to convert to a different database such
** as NDBM, SDBM, or BerkeleyDB.
**
-** $Id: dbbegdbm.c,v 1.1 2000/10/19 01:49:02 drh Exp $
+** $Id: dbbegdbm.c,v 1.2 2001/01/13 14:34:06 drh Exp $
*/
#include "sqliteInt.h"
#include <gdbm.h>
@@ -58,33 +58,14 @@
};
/*
-** The following structure holds the current state of the RC4 algorithm.
-** We use RC4 as a random number generator. Each call to RC4 gives
-** a random 8-bit number.
-**
-** Nothing in this file or anywhere else in SQLite does any kind of
-** encryption. The RC4 algorithm is being used as a PRNG (pseudo-random
-** number generator) not as an encryption device.
-*/
-struct rc4 {
- int i, j;
- int s[256];
-};
-
-/*
** The following structure contains all information used by GDBM
** database driver. This is a subclass of the Dbbe structure.
*/
typedef struct Dbbex Dbbex;
struct Dbbex {
Dbbe dbbe; /* The base class */
- char *zDir; /* The directory containing the database */
int write; /* True for write permission */
BeFile *pOpen; /* List of open files */
- int nTemp; /* Number of temporary files created */
- FILE **apTemp; /* Space to hold temporary file pointers */
- char **azTemp; /* Names of the temporary files */
- struct rc4 rc4; /* The random number generator */
};
/*
@@ -105,41 +86,12 @@
};
/*
-** Initialize the RC4 PRNG. "seed" is a pointer to some random
-** data used to initialize the PRNG.
+**
*/
-static void rc4init(struct rc4 *p, char *seed, int seedlen){
- int i;
- char k[256];
- p->j = 0;
- p->i = 0;
- for(i=0; i<256; i++){
- p->s[i] = i;
- k[i] = seed[i%seedlen];
- }
- for(i=0; i<256; i++){
- int t;
- p->j = (p->j + p->s[i] + k[i]) & 0xff;
- t = p->s[p->j];
- p->s[p->j] = p->s[i];
- p->s[i] = t;
- }
-}
-
-/*
-** Get a single 8-bit random value from the RC4 PRNG.
-*/
-static int rc4byte(struct rc4 *p){
- int t;
- p->i = (p->i + 1) & 0xff;
- p->j = (p->j + p->s[p->i]) & 0xff;
- t = p->s[p->i];
- p->s[p->i] = p->s[p->j];
- p->s[p->j] = t;
- t = p->s[p->i] + p->s[p->j];
- return t & 0xff;
-}
-
+struct DbbeList {
+ FILE *pOut;
+ Dbbe *pDbbe;
+};
/*
** The "mkdir()" function only takes one argument under Windows.
*/
@@ -165,18 +117,7 @@
memset(pFile, 0, sizeof(*pFile));
sqliteFree(pFile);
}
- for(i=0; i<pBe->nTemp; i++){
- if( pBe->apTemp[i]!=0 ){
- unlink(pBe->azTemp[i]);
- fclose(pBe->apTemp[i]);
- sqliteFree(pBe->azTemp[i]);
- pBe->apTemp[i] = 0;
- pBe->azTemp[i] = 0;
- break;
- }
- }
- sqliteFree(pBe->azTemp);
- sqliteFree(pBe->apTemp);
+ sqliteDbbeCloseAllTempFiles(pDbbe);
memset(pBe, 0, sizeof(*pBe));
sqliteFree(pBe);
}
@@ -190,9 +131,9 @@
static char *sqliteFileOfTable(Dbbex *pBe, const char *zTable){
char *zFile = 0;
int i;
- sqliteSetString(&zFile, pBe->zDir, "/", zTable, ".tbl", 0);
+ sqliteSetString(&zFile, pBe->dbbe.zDir, "/", zTable, ".tbl", 0);
if( zFile==0 ) return 0;
- for(i=strlen(pBe->zDir)+1; zFile[i]; i++){
+ for(i=strlen(pBe->dbbe.zDir)+1; zFile[i]; i++){
int c = zFile[i];
if( isupper(c) ){
zFile[i] = tolower(c);
@@ -204,27 +145,6 @@
}
/*
-** Generate a random filename with the given prefix. The new filename
-** is written into zBuf[]. The calling function must insure that
-** zBuf[] is big enough to hold the prefix plus 20 or so extra
-** characters.
-**
-** Very random names are chosen so that the chance of a
-** collision with an existing filename is very very small.
-*/
-static void randomName(struct rc4 *pRc4, char *zBuf, char *zPrefix){
- int i, j;
- static const char zRandomChars[] = "abcdefghijklmnopqrstuvwxyz0123456789";
- strcpy(zBuf, zPrefix);
- j = strlen(zBuf);
- for(i=0; i<15; i++){
- int c = rc4byte(pRc4) % (sizeof(zRandomChars) - 1);
- zBuf[j++] = zRandomChars[c];
- }
- zBuf[j] = 0;
-}
-
-/*
** Open a new table cursor. Write a pointer to the corresponding
** DbbeCursor structure into *ppCursr. Return an integer success
** code:
@@ -295,13 +215,11 @@
}
}else{
int limit;
- struct rc4 *pRc4;
char zRandom[50];
- pRc4 = &pBe->rc4;
zFile = 0;
limit = 5;
do {
- randomName(&pBe->rc4, zRandom, "_temp_table_");
+ sqliteRandomName(zRandom, "_temp_table_");
sqliteFree(zFile);
zFile = sqliteFileOfTable(pBe, zRandom);
pFile->dbf = gdbm_open(zFile, 0, rw_mask, mode, 0);
@@ -577,15 +495,10 @@
datum key;
int go = 1;
int i;
- struct rc4 *pRc4;
if( pCursr->pFile==0 || pCursr->pFile->dbf==0 ) return 1;
- pRc4 = &pCursr->pBe->rc4;
while( go ){
- iKey = 0;
- for(i=0; i<4; i++){
- iKey = (iKey<<8) + rc4byte(pRc4);
- }
+ iKey = sqliteRandomInteger();
if( iKey==0 ) continue;
key.dptr = (char*)&iKey;
key.dsize = 4;
@@ -631,68 +544,31 @@
}
/*
-** Open a temporary file. The file should be deleted when closed.
-**
-** Note that we can't use the old Unix trick of opening the file
-** and then immediately unlinking the file. That works great
-** under Unix, but fails when we try to port to Windows.
+** This variable contains pointers to all of the access methods
+** used to implement the GDBM backend.
*/
-static int sqliteGdbmOpenTempFile(Dbbe *pDbbe, FILE **ppFile){
- char *zFile; /* Full name of the temporary file */
- char zBuf[50]; /* Base name of the temporary file */
- int i; /* Loop counter */
- int limit; /* Prevent an infinite loop */
- int rc = SQLITE_OK; /* Value returned by this function */
- Dbbex *pBe = (Dbbex*)pDbbe;
-
- for(i=0; i<pBe->nTemp; i++){
- if( pBe->apTemp[i]==0 ) break;
- }
- if( i>=pBe->nTemp ){
- pBe->nTemp++;
- pBe->apTemp = sqliteRealloc(pBe->apTemp, pBe->nTemp*sizeof(FILE*) );
- pBe->azTemp = sqliteRealloc(pBe->azTemp, pBe->nTemp*sizeof(char*) );
- }
- if( pBe->apTemp==0 ){
- *ppFile = 0;
- return SQLITE_NOMEM;
- }
- limit = 4;
- zFile = 0;
- do{
- randomName(&pBe->rc4, zBuf, "/_temp_file_");
- sqliteFree(zFile);
- zFile = 0;
- sqliteSetString(&zFile, pBe->zDir, zBuf, 0);
- }while( access(zFile,0)==0 && limit-- >= 0 );
- *ppFile = pBe->apTemp[i] = fopen(zFile, "w+");
- if( pBe->apTemp[i]==0 ){
- rc = SQLITE_ERROR;
- sqliteFree(zFile);
- pBe->azTemp[i] = 0;
- }else{
- pBe->azTemp[i] = zFile;
- }
- return rc;
-}
-
-/*
-** Close a temporary file opened using sqliteGdbmOpenTempFile()
-*/
-static void sqliteGdbmCloseTempFile(Dbbe *pDbbe, FILE *f){
- int i;
- Dbbex *pBe = (Dbbex*)pDbbe;
- for(i=0; i<pBe->nTemp; i++){
- if( pBe->apTemp[i]==f ){
- unlink(pBe->azTemp[i]);
- sqliteFree(pBe->azTemp[i]);
- pBe->apTemp[i] = 0;
- pBe->azTemp[i] = 0;
- break;
- }
- }
- fclose(f);
-}
+static struct DbbeMethods gdbmMethods = {
+ /* n Close */ sqliteGdbmClose,
+ /* OpenCursor */ sqliteGdbmOpenCursor,
+ /* DropTable */ sqliteGdbmDropTable,
+ /* ReorganizeTable */ sqliteGdbmReorganizeTable,
+ /* CloseCursor */ sqliteGdbmCloseCursor,
+ /* Fetch */ sqliteGdbmFetch,
+ /* Test */ sqliteGdbmTest,
+ /* CopyKey */ sqliteGdbmCopyKey,
+ /* CopyData */ sqliteGdbmCopyData,
+ /* ReadKey */ sqliteGdbmReadKey,
+ /* ReadData */ sqliteGdbmReadData,
+ /* KeyLength */ sqliteGdbmKeyLength,
+ /* DataLength */ sqliteGdbmDataLength,
+ /* NextKey */ sqliteGdbmNextKey,
+ /* Rewind */ sqliteGdbmRewind,
+ /* New */ sqliteGdbmNew,
+ /* Put */ sqliteGdbmPut,
+ /* Delete */ sqliteGdbmDelete,
+ /* OpenTempFile */ sqliteDbbeOpenTempFile,
+ /* CloseTempFile */ sqliteDbbeCloseTempFile
+};
/*
@@ -746,31 +622,10 @@
sqliteSetString(pzErrMsg, "out of memory", 0);
return 0;
}
- pNew->dbbe.Close = sqliteGdbmClose;
- pNew->dbbe.OpenCursor = sqliteGdbmOpenCursor;
- pNew->dbbe.DropTable = sqliteGdbmDropTable;
- pNew->dbbe.ReorganizeTable = sqliteGdbmReorganizeTable;
- pNew->dbbe.CloseCursor = sqliteGdbmCloseCursor;
- pNew->dbbe.Fetch = sqliteGdbmFetch;
- pNew->dbbe.Test = sqliteGdbmTest;
- pNew->dbbe.CopyKey = sqliteGdbmCopyKey;
- pNew->dbbe.CopyData = sqliteGdbmCopyData;
- pNew->dbbe.ReadKey = sqliteGdbmReadKey;
- pNew->dbbe.ReadData = sqliteGdbmReadData;
- pNew->dbbe.KeyLength = sqliteGdbmKeyLength;
- pNew->dbbe.DataLength = sqliteGdbmDataLength;
- pNew->dbbe.NextKey = sqliteGdbmNextKey;
- pNew->dbbe.Rewind = sqliteGdbmRewind;
- pNew->dbbe.New = sqliteGdbmNew;
- pNew->dbbe.Put = sqliteGdbmPut;
- pNew->dbbe.Delete = sqliteGdbmDelete;
- pNew->dbbe.OpenTempFile = sqliteGdbmOpenTempFile;
- pNew->dbbe.CloseTempFile = sqliteGdbmCloseTempFile;
- pNew->zDir = (char*)&pNew[1];
- strcpy(pNew->zDir, zName);
+ pNew->dbbe.x = &gdbmMethods;
+ pNew->dbbe.zDir = (char*)&pNew[1];
+ strcpy(pNew->dbbe.zDir, zName);
pNew->write = writeFlag;
pNew->pOpen = 0;
- time(&statbuf.st_ctime);
- rc4init(&pNew->rc4, (char*)&statbuf, sizeof(statbuf));
return &pNew->dbbe;
}
diff --git a/src/dbbemem.c b/src/dbbemem.c
index c811805..89b4aee 100644
--- a/src/dbbemem.c
+++ b/src/dbbemem.c
@@ -28,7 +28,7 @@
**
** This file uses an in-memory hash table as the database backend.
**
-** $Id: dbbemem.c,v 1.5 2000/12/10 18:23:50 drh Exp $
+** $Id: dbbemem.c,v 1.6 2001/01/13 14:34:06 drh Exp $
*/
#include "sqliteInt.h"
#include <sys/stat.h>
@@ -343,20 +343,6 @@
};
/*
-** The following structure holds the current state of the RC4 algorithm.
-** We use RC4 as a random number generator. Each call to RC4 gives
-** a random 8-bit number.
-**
-** Nothing in this file or anywhere else in SQLite does any kind of
-** encryption. The RC4 algorithm is being used as a PRNG (pseudo-random
-** number generator) not as an encryption device.
-*/
-struct rc4 {
- int i, j;
- int s[256];
-};
-
-/*
** The following structure contains all information used by GDBM
** database driver. This is a subclass of the Dbbe structure.
*/
@@ -364,10 +350,6 @@
struct Dbbex {
Dbbe dbbe; /* The base class */
Array tables; /* All tables of the database */
- int nTemp; /* Number of temporary files created */
- FILE **apTemp; /* Space to hold temporary file pointers */
- char **azTemp; /* Names of the temporary files */
- struct rc4 rc4; /* The random number generator */
};
/*
@@ -386,42 +368,6 @@
};
/*
-** Initialize the RC4 PRNG. "seed" is a pointer to some random
-** data used to initialize the PRNG.
-*/
-static void rc4init(struct rc4 *p, char *seed, int seedlen){
- int i;
- char k[256];
- p->j = 0;
- p->i = 0;
- for(i=0; i<256; i++){
- p->s[i] = i;
- k[i] = seed[i%seedlen];
- }
- for(i=0; i<256; i++){
- int t;
- p->j = (p->j + p->s[i] + k[i]) & 0xff;
- t = p->s[p->j];
- p->s[p->j] = p->s[i];
- p->s[i] = t;
- }
-}
-
-/*
-** Get a single 8-bit random value from the RC4 PRNG.
-*/
-static int rc4byte(struct rc4 *p){
- int t;
- p->i = (p->i + 1) & 0xff;
- p->j = (p->j + p->s[p->i]) & 0xff;
- t = p->s[p->i];
- p->s[p->i] = p->s[p->j];
- p->s[p->j] = t;
- t = p->s[p->i] + p->s[p->j];
- return t & 0xff;
-}
-
-/*
** Forward declaration
*/
static void sqliteMemCloseCursor(DbbeCursor *pCursr);
@@ -453,44 +399,12 @@
deleteMTable(pTble);
}
ArrayClear(&pBe->tables);
- for(i=0; i<pBe->nTemp; i++){
- if( pBe->apTemp[i]!=0 ){
- unlink(pBe->azTemp[i]);
- fclose(pBe->apTemp[i]);
- sqliteFree(pBe->azTemp[i]);
- pBe->apTemp[i] = 0;
- pBe->azTemp[i] = 0;
- break;
- }
- }
- sqliteFree(pBe->azTemp);
- sqliteFree(pBe->apTemp);
+ sqliteDbbeCloseAllTempFiles(pDbbe);
memset(pBe, 0, sizeof(*pBe));
sqliteFree(pBe);
}
/*
-** Generate a random filename with the given prefix. The new filename
-** is written into zBuf[]. The calling function must insure that
-** zBuf[] is big enough to hold the prefix plus 20 or so extra
-** characters.
-**
-** Very random names are chosen so that the chance of a
-** collision with an existing filename is very very small.
-*/
-static void randomName(struct rc4 *pRc4, char *zBuf, char *zPrefix){
- int i, j;
- static const char zRandomChars[] = "abcdefghijklmnopqrstuvwxyz0123456789";
- strcpy(zBuf, zPrefix);
- j = strlen(zBuf);
- for(i=0; i<15; i++){
- int c = rc4byte(pRc4) % (sizeof(zRandomChars) - 1);
- zBuf[j++] = zRandomChars[c];
- }
- zBuf[j] = 0;
-}
-
-/*
** Translate the name of an SQL table (or index) into its
** canonical name.
**
@@ -752,14 +666,9 @@
Datum key;
int go = 1;
int i;
- struct rc4 *pRc4;
- pRc4 = &pCursr->pBe->rc4;
while( go ){
- iKey = 0;
- for(i=0; i<4; i++){
- iKey = (iKey<<8) + rc4byte(pRc4);
- }
+ iKey = sqliteRandomInteger();
if( iKey==0 ) continue;
key.p = (char*)&iKey;
key.n = 4;
@@ -804,69 +713,31 @@
}
/*
-** Open a temporary file. The file should be deleted when closed.
-**
-** Note that we can't use the old Unix trick of opening the file
-** and then immediately unlinking the file. That works great
-** under Unix, but fails when we try to port to Windows.
+** This variable contains pointers to all of the access methods
+** used to implement the MEMORY backend.
*/
-static int sqliteMemOpenTempFile(Dbbe *pDbbe, FILE **ppTble){
- char *zName; /* Full name of the temporary file */
- char zBuf[50]; /* Base name of the temporary file */
- int i; /* Loop counter */
- int limit; /* Prevent an infinite loop */
- int rc = SQLITE_OK; /* Value returned by this function */
- Dbbex *pBe = (Dbbex*)pDbbe;
-
- for(i=0; i<pBe->nTemp; i++){
- if( pBe->apTemp[i]==0 ) break;
- }
- if( i>=pBe->nTemp ){
- pBe->nTemp++;
- pBe->apTemp = sqliteRealloc(pBe->apTemp, pBe->nTemp*sizeof(FILE*) );
- pBe->azTemp = sqliteRealloc(pBe->azTemp, pBe->nTemp*sizeof(char*) );
- }
- if( pBe->apTemp==0 ){
- *ppTble = 0;
- return SQLITE_NOMEM;
- }
- limit = 4;
- zName = 0;
- do{
- randomName(&pBe->rc4, zBuf, "/tmp/_temp_file_");
- sqliteFree(zName);
- zName = 0;
- sqliteSetString(&zName, zBuf, 0);
- }while( access(zName,0)==0 && limit-- >= 0 );
- *ppTble = pBe->apTemp[i] = fopen(zName, "w+");
- if( pBe->apTemp[i]==0 ){
- rc = SQLITE_ERROR;
- sqliteFree(zName);
- pBe->azTemp[i] = 0;
- }else{
- pBe->azTemp[i] = zName;
- }
- return rc;
-}
-
-/*
-** Close a temporary file opened using sqliteMemOpenTempFile()
-*/
-static void sqliteMemCloseTempFile(Dbbe *pDbbe, FILE *f){
- int i;
- Dbbex *pBe = (Dbbex*)pDbbe;
- for(i=0; i<pBe->nTemp; i++){
- if( pBe->apTemp[i]==f ){
- unlink(pBe->azTemp[i]);
- sqliteFree(pBe->azTemp[i]);
- pBe->apTemp[i] = 0;
- pBe->azTemp[i] = 0;
- break;
- }
- }
- fclose(f);
-}
-
+static struct DbbeMethods memoryMethods = {
+ /* n Close */ sqliteMemClose,
+ /* OpenCursor */ sqliteMemOpenCursor,
+ /* DropTable */ sqliteMemDropTable,
+ /* ReorganizeTable */ sqliteMemReorganizeTable,
+ /* CloseCursor */ sqliteMemCloseCursor,
+ /* Fetch */ sqliteMemFetch,
+ /* Test */ sqliteMemTest,
+ /* CopyKey */ sqliteMemCopyKey,
+ /* CopyData */ sqliteMemCopyData,
+ /* ReadKey */ sqliteMemReadKey,
+ /* ReadData */ sqliteMemReadData,
+ /* KeyLength */ sqliteMemKeyLength,
+ /* DataLength */ sqliteMemDataLength,
+ /* NextKey */ sqliteMemNextKey,
+ /* Rewind */ sqliteMemRewind,
+ /* New */ sqliteMemNew,
+ /* Put */ sqliteMemPut,
+ /* Delete */ sqliteMemDelete,
+ /* OpenTempFile */ sqliteDbbeOpenTempFile,
+ /* CloseTempFile */ sqliteDbbeCloseTempFile
+};
/*
** This routine opens a new database. For the GDBM driver
@@ -884,7 +755,6 @@
char **pzErrMsg /* Write error messages (if any) here */
){
Dbbex *pNew;
- long now;
pNew = sqliteMalloc( sizeof(*pNew) );
if( pNew==0 ){
@@ -892,27 +762,7 @@
return 0;
}
ArrayInit(&pNew->tables);
- pNew->dbbe.Close = sqliteMemClose;
- pNew->dbbe.OpenCursor = sqliteMemOpenCursor;
- pNew->dbbe.DropTable = sqliteMemDropTable;
- pNew->dbbe.ReorganizeTable = sqliteMemReorganizeTable;
- pNew->dbbe.CloseCursor = sqliteMemCloseCursor;
- pNew->dbbe.Fetch = sqliteMemFetch;
- pNew->dbbe.Test = sqliteMemTest;
- pNew->dbbe.CopyKey = sqliteMemCopyKey;
- pNew->dbbe.CopyData = sqliteMemCopyData;
- pNew->dbbe.ReadKey = sqliteMemReadKey;
- pNew->dbbe.ReadData = sqliteMemReadData;
- pNew->dbbe.KeyLength = sqliteMemKeyLength;
- pNew->dbbe.DataLength = sqliteMemDataLength;
- pNew->dbbe.NextKey = sqliteMemNextKey;
- pNew->dbbe.Rewind = sqliteMemRewind;
- pNew->dbbe.New = sqliteMemNew;
- pNew->dbbe.Put = sqliteMemPut;
- pNew->dbbe.Delete = sqliteMemDelete;
- pNew->dbbe.OpenTempFile = sqliteMemOpenTempFile;
- pNew->dbbe.CloseTempFile = sqliteMemCloseTempFile;
- time(&now);
- rc4init(&pNew->rc4, (char*)&now, sizeof(now));
+ pNew->dbbe.x = &memoryMethods;
+ pNew->dbbe.zDir = 0;
return &pNew->dbbe;
}
diff --git a/src/main.c b/src/main.c
index 0a21177..a707b67 100644
--- a/src/main.c
+++ b/src/main.c
@@ -26,7 +26,7 @@
** other files are for internal use by SQLite and should not be
** accessed by users of the library.
**
-** $Id: main.c,v 1.22 2000/12/10 18:23:50 drh Exp $
+** $Id: main.c,v 1.23 2001/01/13 14:34:06 drh Exp $
*/
#include "sqliteInt.h"
@@ -239,7 +239,7 @@
*/
void sqlite_close(sqlite *db){
int i;
- db->pBe->Close(db->pBe);
+ db->pBe->x->Close(db->pBe);
for(i=0; i<N_HASH; i++){
Table *pNext, *pList = db->apTblHash[i];
db->apTblHash[i] = 0;
diff --git a/src/random.c b/src/random.c
new file mode 100644
index 0000000..726fefe
--- /dev/null
+++ b/src/random.c
@@ -0,0 +1,127 @@
+/*
+** Copyright (c) 2000 D. Richard Hipp
+**
+** This program is free software; you can redistribute it and/or
+** modify it under the terms of the GNU General Public
+** License as published by the Free Software Foundation; either
+** version 2 of the License, or (at your option) any later version.
+**
+** This program is distributed in the hope that it will be useful,
+** but WITHOUT ANY WARRANTY; without even the implied warranty of
+** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+** General Public License for more details.
+**
+** You should have received a copy of the GNU General Public
+** License along with this library; if not, write to the
+** Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+** Boston, MA 02111-1307, USA.
+**
+** Author contact information:
+** drh@hwaci.com
+** http://www.hwaci.com/drh/
+**
+*************************************************************************
+** This file contains code to implement a pseudo-random number
+** generator (PRNG) for SQLite.
+**
+** Random numbers are used by some of the database backends in order
+** to generate random integer keys for tables or random filenames.
+**
+** $Id: random.c,v 1.1 2001/01/13 14:34:07 drh Exp $
+*/
+#include "sqliteInt.h"
+
+
+/*
+** Get a single 8-bit random value from the RC4 PRNG.
+*/
+int sqliteRandomByte(void){
+ int t;
+
+ /*
+ ** The following structure holds the current state of the RC4 algorithm.
+ ** We use RC4 as a random number generator. Each call to RC4 gives
+ ** a random 8-bit number.
+ **
+ ** Nothing in this file or anywhere else in SQLite does any kind of
+ ** encryption. The RC4 algorithm is being used as a PRNG (pseudo-random
+ ** number generator) not as an encryption device.
+ */
+ static struct {
+ int isInit;
+ int i, j;
+ int s[256];
+ } prng_state;
+
+ /* Initialize the state of the random number generator once,
+ ** the first time this routine is called. The seed value does
+ ** not need to contain a lot of randomness since we are not
+ ** trying to do secure encryption or anything like that...
+ */
+ if( !prng_state.isInit ){
+ int i;
+ static char seed[] = " sqlite random seed";
+ char k[256];
+ time((time_t*)seed);
+ prng_state.j = 0;
+ prng_state.i = 0;
+ for(i=0; i<256; i++){
+ prng_state.s[i] = i;
+ k[i] = seed[i%sizeof(seed)];
+ }
+ for(i=0; i<256; i++){
+ int t;
+ prng_state.j = (prng_state.j + prng_state.s[i] + k[i]) & 0xff;
+ t = prng_state.s[prng_state.j];
+ prng_state.s[prng_state.j] = prng_state.s[i];
+ prng_state.s[i] = t;
+ }
+ prng_state.isInit = 1;
+ }
+
+ /* Generate and return single random byte
+ */
+ prng_state.i = (prng_state.i + 1) & 0xff;
+ prng_state.j = (prng_state.j + prng_state.s[prng_state.i]) & 0xff;
+ t = prng_state.s[prng_state.i];
+ prng_state.s[prng_state.i] = prng_state.s[prng_state.j];
+ prng_state.s[prng_state.j] = t;
+ t = prng_state.s[prng_state.i] + prng_state.s[prng_state.j];
+ return t & 0xff;
+}
+
+/*
+** Return a random 32-bit integer. The integer is generated by making
+** 4 calls to sqliteRandomByte().
+*/
+int sqliteRandomInteger(void){
+ int r;
+ int i;
+ r = sqliteRandomByte();
+ for(i=1; i<4; i++){
+ r = (r<<8) + sqliteRandomByte();
+ }
+ return r;
+}
+
+
+/*
+** Generate a random filename with the given prefix. The new filename
+** is written into zBuf[]. The calling function must insure that
+** zBuf[] is big enough to hold the prefix plus 20 or so extra
+** characters.
+**
+** Very random names are chosen so that the chance of a
+** collision with an existing filename is very very small.
+*/
+void sqliteRandomName(char *zBuf, char *zPrefix){
+ int i, j;
+ static const char zRandomChars[] = "abcdefghijklmnopqrstuvwxyz0123456789";
+ strcpy(zBuf, zPrefix);
+ j = strlen(zBuf);
+ for(i=0; i<15; i++){
+ int c = sqliteRandomByte() % (sizeof(zRandomChars) - 1);
+ zBuf[j++] = zRandomChars[c];
+ }
+ zBuf[j] = 0;
+}
diff --git a/src/sqliteInt.h b/src/sqliteInt.h
index 5b777ef..b6e6021 100644
--- a/src/sqliteInt.h
+++ b/src/sqliteInt.h
@@ -23,7 +23,7 @@
*************************************************************************
** Internal interface definitions for SQLite.
**
-** @(#) $Id: sqliteInt.h,v 1.33 2000/12/10 18:23:51 drh Exp $
+** @(#) $Id: sqliteInt.h,v 1.34 2001/01/13 14:34:07 drh Exp $
*/
#include "sqlite.h"
#include "dbbe.h"
@@ -419,3 +419,8 @@
int sqliteExprAnalyzeAggregates(Parse*, Expr*);
void sqliteParseInfoReset(Parse*);
Vdbe *sqliteGetVdbe(Parse*);
+int sqliteRandomByte(void);
+int sqliteRandomInteger(void);
+void sqliteRandomName(char*,char*);
+int sqliteDbbeOpenTempFile(Dbbe*, FILE**);
+void sqliteDbbeCloseTempFile(Dbbe*, FILE*);
diff --git a/src/vdbe.c b/src/vdbe.c
index bfdb65b..749f1e0 100644
--- a/src/vdbe.c
+++ b/src/vdbe.c
@@ -41,7 +41,7 @@
** But other routines are also provided to help in building up
** a program instruction by instruction.
**
-** $Id: vdbe.c,v 1.49 2000/12/10 18:35:20 drh Exp $
+** $Id: vdbe.c,v 1.50 2001/01/13 14:34:07 drh Exp $
*/
#include "sqliteInt.h"
#include <unistd.h>
@@ -696,7 +696,7 @@
p->azColName = 0;
for(i=0; i<p->nCursor; i++){
if( p->aCsr[i].pCursor ){
- p->pBe->CloseCursor(p->aCsr[i].pCursor);
+ p->pBe->x->CloseCursor(p->aCsr[i].pCursor);
p->aCsr[i].pCursor = 0;
}
}
@@ -713,7 +713,7 @@
p->nMem = 0;
for(i=0; i<p->nList; i++){
if( p->apList[i] ){
- p->pBe->CloseTempFile(p->pBe, p->apList[i]);
+ p->pBe->x->CloseTempFile(p->pBe, p->apList[i]);
p->apList[i] = 0;
}
}
@@ -953,6 +953,7 @@
Op *pOp; /* Current operation */
int rc; /* Value to return */
Dbbe *pBe = p->pBe; /* The backend driver */
+ DbbeMethods *pBex = pBe->x; /* The backend driver methods */
sqlite *db = p->db; /* The database */
char **zStack;
Stack *aStack;
@@ -1809,10 +1810,10 @@
for(j=p->nCursor; j<=i; j++) p->aCsr[j].pCursor = 0;
p->nCursor = i+1;
}else if( p->aCsr[i].pCursor ){
- pBe->CloseCursor(p->aCsr[i].pCursor);
+ pBex->CloseCursor(p->aCsr[i].pCursor);
}
do {
- rc = pBe->OpenCursor(pBe,pOp->p3,pOp->p2,&p->aCsr[i].pCursor);
+ rc = pBex->OpenCursor(pBe,pOp->p3,pOp->p2,&p->aCsr[i].pCursor);
switch( rc ){
case SQLITE_BUSY: {
if( xBusy==0 || (*xBusy)(pBusyArg, pOp->p3, ++busy)==0 ){
@@ -1853,7 +1854,7 @@
case OP_Close: {
int i = pOp->p1;
if( i>=0 && i<p->nCursor && p->aCsr[i].pCursor ){
- pBe->CloseCursor(p->aCsr[i].pCursor);
+ pBex->CloseCursor(p->aCsr[i].pCursor);
p->aCsr[i].pCursor = 0;
}
break;
@@ -1871,11 +1872,11 @@
VERIFY( if( tos<0 ) goto not_enough_stack; )
if( i>=0 && i<p->nCursor && p->aCsr[i].pCursor ){
if( aStack[tos].flags & STK_Int ){
- pBe->Fetch(p->aCsr[i].pCursor, sizeof(int),
+ pBex->Fetch(p->aCsr[i].pCursor, sizeof(int),
(char*)&aStack[tos].i);
}else{
if( Stringify(p, tos) ) goto no_mem;
- pBe->Fetch(p->aCsr[i].pCursor, aStack[tos].n,
+ pBex->Fetch(p->aCsr[i].pCursor, aStack[tos].n,
zStack[tos]);
}
p->nFetch++;
@@ -1937,11 +1938,11 @@
VERIFY( if( tos<0 ) goto not_enough_stack; )
if( VERIFY( i>=0 && i<p->nCursor && ) p->aCsr[i].pCursor ){
if( aStack[tos].flags & STK_Int ){
- alreadyExists = pBe->Test(p->aCsr[i].pCursor, sizeof(int),
+ alreadyExists = pBex->Test(p->aCsr[i].pCursor, sizeof(int),
(char*)&aStack[tos].i);
}else{
if( Stringify(p, tos) ) goto no_mem;
- alreadyExists = pBe->Test(p->aCsr[i].pCursor,aStack[tos].n,
+ alreadyExists = pBex->Test(p->aCsr[i].pCursor,aStack[tos].n,
zStack[tos]);
}
}
@@ -1967,7 +1968,7 @@
if( VERIFY( i<0 || i>=p->nCursor || ) p->aCsr[i].pCursor==0 ){
v = 0;
}else{
- v = pBe->New(p->aCsr[i].pCursor);
+ v = pBex->New(p->aCsr[i].pCursor);
}
VERIFY( NeedStack(p, p->tos+1); )
p->tos++;
@@ -2000,7 +2001,7 @@
nKey = sizeof(int);
zKey = (char*)&aStack[nos].i;
}
- pBe->Put(p->aCsr[i].pCursor, nKey, zKey,
+ pBex->Put(p->aCsr[i].pCursor, nKey, zKey,
aStack[tos].n, zStack[tos]);
}
POPSTACK;
@@ -2028,7 +2029,7 @@
nKey = aStack[tos].n;
zKey = zStack[tos];
}
- pBe->Delete(p->aCsr[i].pCursor, nKey, zKey);
+ pBex->Delete(p->aCsr[i].pCursor, nKey, zKey);
}
POPSTACK;
break;
@@ -2082,29 +2083,29 @@
VERIFY( if( NeedStack(p, tos) ) goto no_mem; )
if( VERIFY( i>=0 && i<p->nCursor && ) (pCrsr = p->aCsr[i].pCursor)!=0 ){
if( p->aCsr[i].keyAsData ){
- amt = pBe->KeyLength(pCrsr);
+ amt = pBex->KeyLength(pCrsr);
if( amt<=sizeof(int)*(p2+1) ){
aStack[tos].flags = STK_Null;
break;
}
- pAddr = (int*)pBe->ReadKey(pCrsr, sizeof(int)*p2);
+ pAddr = (int*)pBex->ReadKey(pCrsr, sizeof(int)*p2);
if( *pAddr==0 ){
aStack[tos].flags = STK_Null;
break;
}
- z = pBe->ReadKey(pCrsr, *pAddr);
+ z = pBex->ReadKey(pCrsr, *pAddr);
}else{
- amt = pBe->DataLength(pCrsr);
+ amt = pBex->DataLength(pCrsr);
if( amt<=sizeof(int)*(p2+1) ){
aStack[tos].flags = STK_Null;
break;
}
- pAddr = (int*)pBe->ReadData(pCrsr, sizeof(int)*p2);
+ pAddr = (int*)pBex->ReadData(pCrsr, sizeof(int)*p2);
if( *pAddr==0 ){
aStack[tos].flags = STK_Null;
break;
}
- z = pBe->ReadData(pCrsr, *pAddr);
+ z = pBex->ReadData(pCrsr, *pAddr);
}
zStack[tos] = z;
aStack[tos].n = strlen(z) + 1;
@@ -2127,11 +2128,11 @@
VERIFY( if( NeedStack(p, p->tos) ) goto no_mem; )
if( VERIFY( i>=0 && i<p->nCursor && ) (pCrsr = p->aCsr[i].pCursor)!=0 ){
- char *z = pBe->ReadKey(pCrsr, 0);
+ char *z = pBex->ReadKey(pCrsr, 0);
if( p->aCsr[i].keyAsData ){
zStack[tos] = z;
aStack[tos].flags = STK_Str;
- aStack[tos].n = pBe->KeyLength(pCrsr);
+ aStack[tos].n = pBex->KeyLength(pCrsr);
}else{
memcpy(&aStack[tos].i, z, sizeof(int));
aStack[tos].flags = STK_Int;
@@ -2148,7 +2149,7 @@
case OP_Rewind: {
int i = pOp->p1;
if( VERIFY( i>=0 && i<p->nCursor && ) p->aCsr[i].pCursor!=0 ){
- pBe->Rewind(p->aCsr[i].pCursor);
+ pBex->Rewind(p->aCsr[i].pCursor);
}
break;
}
@@ -2161,7 +2162,7 @@
case OP_Next: {
int i = pOp->p1;
if( VERIFY( i>=0 && i<p->nCursor && ) p->aCsr[i].pCursor!=0 ){
- if( pBe->NextKey(p->aCsr[i].pCursor)==0 ){
+ if( pBex->NextKey(p->aCsr[i].pCursor)==0 ){
pc = pOp->p2 - 1;
}else{
p->nFetch++;
@@ -2211,8 +2212,8 @@
int *aIdx;
int nIdx;
int j, k;
- nIdx = pBe->DataLength(pCrsr)/sizeof(int);
- aIdx = (int*)pBe->ReadData(pCrsr, 0);
+ nIdx = pBex->DataLength(pCrsr)/sizeof(int);
+ aIdx = (int*)pBex->ReadData(pCrsr, 0);
if( nIdx>1 ){
k = *(aIdx++);
if( k>nIdx-1 ) k = nIdx-1;
@@ -2257,10 +2258,10 @@
Integerify(p, nos);
newVal = aStack[nos].i;
if( Stringify(p, tos) ) goto no_mem;
- r = pBe->Fetch(pCrsr, aStack[tos].n, zStack[tos]);
+ r = pBex->Fetch(pCrsr, aStack[tos].n, zStack[tos]);
if( r==0 ){
/* Create a new record for this index */
- pBe->Put(pCrsr, aStack[tos].n, zStack[tos],
+ pBex->Put(pCrsr, aStack[tos].n, zStack[tos],
sizeof(int), (char*)&newVal);
}else{
/* Extend the existing record */
@@ -2268,32 +2269,32 @@
int *aIdx;
int k;
- nIdx = pBe->DataLength(pCrsr)/sizeof(int);
+ nIdx = pBex->DataLength(pCrsr)/sizeof(int);
if( nIdx==1 ){
aIdx = sqliteMalloc( sizeof(int)*4 );
if( aIdx==0 ) goto no_mem;
aIdx[0] = 2;
- pBe->CopyData(pCrsr, 0, sizeof(int), (char*)&aIdx[1]);
+ pBex->CopyData(pCrsr, 0, sizeof(int), (char*)&aIdx[1]);
aIdx[2] = newVal;
- pBe->Put(pCrsr, aStack[tos].n, zStack[tos],
+ pBex->Put(pCrsr, aStack[tos].n, zStack[tos],
sizeof(int)*4, (char*)aIdx);
sqliteFree(aIdx);
}else{
- aIdx = (int*)pBe->ReadData(pCrsr, 0);
+ aIdx = (int*)pBex->ReadData(pCrsr, 0);
k = aIdx[0];
if( k<nIdx-1 ){
aIdx[k+1] = newVal;
aIdx[0]++;
- pBe->Put(pCrsr, aStack[tos].n, zStack[tos],
+ pBex->Put(pCrsr, aStack[tos].n, zStack[tos],
sizeof(int)*nIdx, (char*)aIdx);
}else{
nIdx *= 2;
aIdx = sqliteMalloc( sizeof(int)*nIdx );
if( aIdx==0 ) goto no_mem;
- pBe->CopyData(pCrsr, 0, sizeof(int)*(k+1), (char*)aIdx);
+ pBex->CopyData(pCrsr, 0, sizeof(int)*(k+1), (char*)aIdx);
aIdx[k+1] = newVal;
aIdx[0]++;
- pBe->Put(pCrsr, aStack[tos].n, zStack[tos],
+ pBex->Put(pCrsr, aStack[tos].n, zStack[tos],
sizeof(int)*nIdx, (char*)aIdx);
sqliteFree(aIdx);
}
@@ -2333,12 +2334,12 @@
Integerify(p, nos);
oldVal = aStack[nos].i;
if( Stringify(p, tos) ) goto no_mem;
- r = pBe->Fetch(pCrsr, aStack[tos].n, zStack[tos]);
+ r = pBex->Fetch(pCrsr, aStack[tos].n, zStack[tos]);
if( r==0 ) break;
- nIdx = pBe->DataLength(pCrsr)/sizeof(int);
- aIdx = (int*)pBe->ReadData(pCrsr, 0);
+ nIdx = pBex->DataLength(pCrsr)/sizeof(int);
+ aIdx = (int*)pBex->ReadData(pCrsr, 0);
if( (nIdx==1 && aIdx[0]==oldVal) || (aIdx[0]==1 && aIdx[1]==oldVal) ){
- pBe->Delete(pCrsr, aStack[tos].n, zStack[tos]);
+ pBex->Delete(pCrsr, aStack[tos].n, zStack[tos]);
}else{
k = aIdx[0];
for(j=1; j<=k && aIdx[j]!=oldVal; j++){}
@@ -2349,7 +2350,7 @@
if( aIdx[0]*3 + 1 < nIdx ){
nIdx /= 2;
}
- pBe->Put(pCrsr, aStack[tos].n, zStack[tos],
+ pBex->Put(pCrsr, aStack[tos].n, zStack[tos],
sizeof(int)*nIdx, (char*)aIdx);
}
}
@@ -2365,7 +2366,7 @@
** from the disk.
*/
case OP_Destroy: {
- pBe->DropTable(pBe, pOp->p3);
+ pBex->DropTable(pBe, pOp->p3);
break;
}
@@ -2374,7 +2375,7 @@
** Compress, optimize, and tidy up the GDBM file named by P3.
*/
case OP_Reorganize: {
- pBe->ReorganizeTable(pBe, pOp->p3);
+ pBex->ReorganizeTable(pBe, pOp->p3);
break;
}
@@ -2396,9 +2397,9 @@
for(j=p->nList; j<=i; j++) p->apList[j] = 0;
p->nList = i+1;
}else if( p->apList[i] ){
- pBe->CloseTempFile(pBe, p->apList[i]);
+ pBex->CloseTempFile(pBe, p->apList[i]);
}
- rc = pBe->OpenTempFile(pBe, &p->apList[i]);
+ rc = pBex->OpenTempFile(pBe, &p->apList[i]);
if( rc!=SQLITE_OK ){
sqliteSetString(pzErrMsg, "unable to open a temporary file", 0);
}
@@ -2468,7 +2469,7 @@
int i = pOp->p1;
VERIFY( if( i<0 ) goto bad_instruction; )
if( VERIFY( i<p->nList && ) p->apList[i]!=0 ){
- pBe->CloseTempFile(pBe, p->apList[i]);
+ pBex->CloseTempFile(pBe, p->apList[i]);
p->apList[i] = 0;
}
break;